The invention is in the field of vehicular maintenance and is a companion to U.S. Pat. No. 5,289,837 issued Mar. 1, 1994 on a ENGINE CLEANING SYSTEM. That unit was a self-contained system that purged the fuel passageways of an internal combustion engine. The instant invention addresses the transmission rather than the engine, replacing the fluid rather than scrubbing the passageways.
Transmission fluid ("oil") should be replaced periodically over the full life of an automatic transmission if its lifespan is to be maximized. Traditionally this has been done by removing the transmission oil pan with the old oil in it, dumping it and refilling the system with new oil. Unlike the crankcase, the transmission does not have a convenient drain opening at the bottom of the pan. Alternatively, some commercial systems draw the fluid out through the fill spout.
Unfortunately both of these techniques suffer from the same drawback. Whereas they both replace the oil in the pan, this represents only 25% to 35% of the total fluid in the system, the rest of which at any given time will reside in the transmission's torque converter, valve box, clutch chamber, fluid cooling system and in other inaccessible passageways.
Ideally these passageways and compartments should be flushed and the resident oil replaced as well as the fluid in the pan. In addition to removing any debris from wearing parts, the high temperatures at which transmissions operate cause the breakdown of the fluid and its lubricating capacity, so new fluid is needed whether or not actual debris is found in the fluid or on transmission surfaces, and the entire volume of oil in the transmission housing should be replaced. Because of the relative complexity of the job compared to oil changes, and the fact that only a fraction of the fluid is replaced anyway unless the fluid replacement is performed multiple times separated by periods of engine operation, fluid is not replaced as often as it should be and transmission deterioration progresses accordingly.
There is a need for a simple machine which has the capability of flushing the entire transmission and replacing the fluid at the same time, and in one operation, obviating repetitious steps while leaving no pools of untouched fluid in the recesses of the transmission.